As environmental issues increasingly arise all over the world, regulations on harmful gas generated from a variety of pollution sources are being tightened. For example, in Korea, a law for tightening the regulations on ultrafine particles in vehicles will be enforced in 2015.
Gas from a pollution source such as a vehicle, a factory, a boiler, and the like include harmful gas which is harmful to the human body or causes environmental pollution, and fine particles like as granular material.
A related-art method for purifying air in vehicles uses a filter which is used in the vehicles. However, the filter rarely reduces harmful gas. In addition, an ionizer air cleaner is being sold, but is merely an ion generating device and lacks the capability of purifying.
Therefore, techniques for removing harmful gas and particles (in particular, fine particles) simultaneously and effectively are developing. For example, Korean Patent Registration Nos. 530973 and 623853 disclose that an activated carbon filter is installed at a front portion or a rear portion of an electrostatic precipitator to process harmful gas and fine particles. However, since the related-art methods require the electrostatic precipitator and the separate activated carbon filter, the size of the processing device increases. In addition, since the processing device has a complicated structure, the costs for installing and maintaining increase.
Korean Patent Registration No. 1087055 discloses an electrostatic precipitator which uses an activated carbon fiber filter which charges and processes particles simultaneously. However, though this electrostatic precipitator can be miniaturized, efficiency is low because it is difficult to apply high voltage to a discharge electrode and ozone generation rate is high.